Using XCode's unit testing framework with Sparrow

Morgan Johnson

Hi All. I'm fairly new to Sparrow (last 4 weeks using it to develop a game). It's awesome! Well done to all involved.

However I am having one significant issue. I'm a modern software developer 🙂 That means I use test driven development: I write a failing unit test then write the code to make it pass. It's a fantastic way to work that saves heaps of time in the long term and improves quality out of site.

Most of Sparrow is very compatible with this approach. My tests can send Sparrow events to objects and see how they react.

But I am having a heap of trouble getting my media to load in test runs. All the texture loads and audio loads are failing. I've resorted to having a separate copy of the Media.m file that produces dummy versions of all the media to test against. While that's not a bad option it is a pain and means that some parts of the application aren't being properly tested.

Any hints from anyone about how they've worked around this?

Daniel

Hi Morgan!
First of all, thanks a lot for the compliments about Sparrow, and welcome to the Sparrow forum! =)

I've stumbled over this problem myself in the past, it's easy to overlook in Xcode 4. You probably didn't add the images to the test target in Xcode. You can do that under Build Phases -> Copy Bundle Resources.

If you open up the Sparrow project itself, you can see how that works, because the Sparrow unit tests do it just like that.

One more thing: there are some methods that just can't be tested well from within a unit test, because of the OpenGL set-up that would be required. But where it was possible, I wrote the code in a way that supports being tested. (Though I admit I *should* spend more time on that *g*.)

I hope that helps!!

Morgan Johnson

Thanks for your response Daniel. I did have the bundle resources in the test scheme so I don't think that's the issue. But I took your advice and had a look at how you do unit testing of Sparrow. I think the problem is the one you mentioned: many of the OpenGL functions don't work in test mode. So it's really not possible (as far as I can tell) to write tests that actually confirm what's drawn. That's a bit of a shame but I can't really see a way around it.

Having said that I've found it's not too much trouble to have test versions for my media. What I do is use subclasses of Sparrow classes that record when textures are displayed rather than attempting to display them. That way I can check that all my logic works without actually having to check what's really displayed. I'm happy with this approach and it means the tests run super fast (just a few seconds for a full suite of tests).

Not sure if anyone else would be interested in this approach but happy to post the code for my test Media.m file if there's any interest. I must admit I'm a bit obsessive about tests but it's a fantastic thing to have a fully functioning game and know that I can make radical changes to the physics or add new things and be confident nothing is broken without even running the game.

Daniel

It's a good idea to do it that way, the subclassing-approach should work just fine!
And I totally see what you mean -- it always bugged me that I can't unit-test all the parts of Sparrow. It would be high time to enhance Sparrow in that respect. 😉